U.S. patent application number 10/899047 was filed with the patent office on 2005-02-24 for adhesive tape and edging method using same.
This patent application is currently assigned to SEIKO EPSON CORPORATION. Invention is credited to Katagiri, Hiroshi, Kawase, Akiko, Suzuki, Keiichi, Takeshita, Katsuyoshi.
Application Number | 20050042977 10/899047 |
Document ID | / |
Family ID | 32828882 |
Filed Date | 2005-02-24 |
United States Patent
Application |
20050042977 |
Kind Code |
A1 |
Kawase, Akiko ; et
al. |
February 24, 2005 |
Adhesive tape and edging method using same
Abstract
An adhesive tape which is to be arranged between a lens and at
least one of a plurality of chucks in an edge-machining apparatus
comprises an adhesive face for being in contact with the lens. A
measurement of an adhesive strength of the adhesive face is 4 gf
(0.0392 N) or more when a polyethylene terephthalate plate which
has been subjected to a surface treatment with a fluorine-modified
silicone parting agent is used as a test plate in an adhesive
strength test method based on a 180.degree.-peeling method as
defined in JIS Z 0237 "adhesive tape/adhesive sheet test method". A
technique which can be used to edge the lens in which an
antifouling layer is formed by using a fluorine-containing silane
compound having an excellent antifouling effect is also
provided.
Inventors: |
Kawase, Akiko; (Nagano-ken,
JP) ; Katagiri, Hiroshi; (Naganoken, JP) ;
Suzuki, Keiichi; (Naganoken, JP) ; Takeshita,
Katsuyoshi; (Minowamachi, JP) |
Correspondence
Address: |
SUGHRUE MION, PLLC
2100 PENNSYLVANIA AVENUE, N.W.
SUITE 800
WASHINGTON
DC
20037
US
|
Assignee: |
SEIKO EPSON CORPORATION
|
Family ID: |
32828882 |
Appl. No.: |
10/899047 |
Filed: |
July 27, 2004 |
Related U.S. Patent Documents
|
|
|
|
|
|
Application
Number |
Filing Date |
Patent Number |
|
|
10899047 |
Jul 27, 2004 |
|
|
|
PCT/JP03/15192 |
Nov 27, 2003 |
|
|
|
Current U.S.
Class: |
451/41 |
Current CPC
Class: |
B24B 9/14 20130101; Y10T
428/2848 20150115; B24B 13/005 20130101; C09J 7/10 20180101; C09J
7/38 20180101 |
Class at
Publication: |
451/041 |
International
Class: |
B24B 001/00 |
Foreign Application Data
Date |
Code |
Application Number |
Jan 27, 2003 |
JP |
2003-017552 |
Nov 20, 2003 |
JP |
2003-390682 |
Claims
1. An adhesive tape which is provided between a lens and at least
one of a plurality of chucks in an edge-machining apparatus,
comprising an adhesive face for being in contact with the lens and
having a measurement value of an adhesive strength of the adhesive
face being 4 gf (0.0392 N) or more when a polyethylene
terephthalate plate which has been subjected to a surface treatment
with a fluorine-modified silicone parting agent is used as a test
plate in an adhesive strength test method based on a
180.degree.-peeling method as defined in JIS Z 0237 "adhesive
tape/adhesive sheet test method".
2. The adhesive tape as set forth in claim 1, wherein a
bored-through hole is provided in the central portion of adhesive
tape.
3. An edging method, comprising the steps of: attaching an adhesive
tape on an antifouling layer of a lens on which the antifouling
layer is provided; and edging the lens by an edge-machining
apparatus while the lens is held by a plurality of chucks such that
the adhesive tape is interposed between the lens and at least one
of the plurality of chucks in the edge-machining apparatus.
4. The edging method as set forth in claim 3, wherein the adhesive
tape comprises an adhesive face for being contact with the lens and
having a measurement value of an adhesive strength of the adhesive
face of 4 gf (0.0392 N) or more when a polyethylene terephthalate
plate which has been subjected to a surface treatment with a
fluorine-modified silicone parting agent is used as a test plate in
an adhesive strength test method based on a 180.degree.-peeling
method as defined in JIS Z 0237 "adhesive tape/adhesive sheet test
method".
5. The edging method as set forth in claim 3, wherein the
antifouling layer is formed by using as a main component a
fluorine-containing silane compound as represented by the following
general formula (1): 4wherein R.sub.f represents a straight or
branched perfluoroalkyl group having from 1 to 16 carbon atoms; X
represents iodine or hydrogen; Y represents hydrogen or a lower
alkyl group; Z represents fluorine or a trifluoromethyl group;
R.sup.1 represents a hydrolysable group; R.sup.2 represents
hydrogen or an inactive monovalent organic group; a, b, c, and d
each individually represents an integer of from 0 to 200; e
represents 0 or 1; m and n each individually represents an integer
of from 0 to 2; and p represents an integer of from 1 to 10.
6. The edging method as claim 3, wherein the adhesive tape is
attached to the concave face of the lens.
7. The edging method as claim 4, wherein the adhesive tape is
attached to the concave face of the lens.
8. The edging method as claim 5, wherein the adhesive tape is
attached to the concave face of the lens.
9. The edging method as claim 3, wherein the plurality of chucks is
a pair.
Description
[0001] This application is a Continuation application of the
international application PCT/JP03/015192 filed Nov. 27, 2003 and
claims priority from Japan 2003-017552 filed Jan. 27, 2003 and
Japan 2003-390682 filed Nov. 20, 2003, all of which is incorporated
herein by reference.
TECHNICAL FIELD
[0002] The present invention relates to an adhesive tape for use in
edging and an edging method and, particularly, to an adhesive tape
favorable for edging of a lens provided with an antifouling layer
and an edging method.
BACKGROUND OF THE INVENTION
[0003] In order to suppress reflection of light or increase
transmittance of the light, a reflection reducing coating is
ordinarily formed on a surface of a lens, such as a spectacle lens.
There is a problem in that, at the time of use, a stain derived
from adherence of, for example, dirt from a hand, a fingerprint,
perspiration, or cosmetic is conspicuous and it is hard to remove
the stain. In coping with this problem, in order to prevent the
stain from adhering or to facilitate removal of the stain whenever
adhered, an antifouling layer has further been provided on a
surface of the reflection reducing coating.
[0004] With regard to a surface treating agent for providing the
antifouling layer on the spectacle lens, a fluorine-containing
silane compound which is described in JP-A No. 9-258003 to form the
antifouling layer is favorable in terms of the antifouling
property. Further, the effect thereof lasts long.
[0005] However, the lens which has been subjected to the surface
treatment with the fluorine-containing silane compound as described
in the above publication has an extremely small friction
coefficient compared to that obtained by using a conventional
surface treating agent. Therefore, the surface of the lens has such
a characteristic as being too slippery. Due to this characteristic,
a problem as described below occurs when the lens is subjected to
edging. At a retail shop of spectacles, grinding a round spectacle
lens to be in a shape in which the lens can be inserted in a
spectacle frame, namely, so-called edging has been performed.
[0006] In the edging, first, a machining center of the spectacle
lens is sucked and held by chucks of an edge-machining apparatus.
In another case, the machining center of the spectacle lens is
clamped while being applied with pressure from both sides of the
lens. In a manner as described above, an edge of the spectacle lens
is ground by a grinding stone while the spectacle lens is held by a
frictional force. Since the surface of the lens held by the chucks
has good slipperiness, when the lens is ground by a grinding stone,
the lens slips out of position, due to a grinding pressure of the
grinding stone against the chucks, namely, a so-called axial
misalignment occurs. This causes a problem in that precise edging
can not be performed.
[0007] Under these circumstances, the present invention has been
achieved and has an object to provide a technique capable of
allowing edging a lens on which an antifouling layer has been
formed by using a fluorine-containing silane compound excellent in
an antifouling effect.
SUMMARY OF THE INVENTION
[0008] In order to attain the aforementioned object, the present
inventors have exerted an intensive study and, as a result, have
found an adhesive tape having an excellent adhesive strength
against an antifouling layer on a surface of a lens with which
chucks of an edge-machining apparatus are allowed to be in
contact.
[0009] The present inventors have conducted a test by using a
stainless steel plate as a test plate as described in an adhesive
strength test of an adhesive tape in JIS Z 0237 "adhesive
tape/adhesive sheet test method". However, as a result, it has been
found that there is no difference at all between a measurement
value of the adhesive strength of the adhesive tape having an
excellent adhesive strength and a measurement value of the adhesive
strength of the adhesive tape having an inferior adhesive strength
against the lens on which the antifouling layer has been
provided.
[0010] Therefore, the present inventors have studied a method for
distinguishing from others, the adhesive tape having the excellent
adhesive strength against the lens on which the antifouling layer
is formed by using the fluorine-containing silane compound.
Specifically, the present inventors have conducted a test of the
adhesive strength of an adhesive tape by using a polyethylene
terephthalate plate which has been subjected to a surface treatment
by using a fluorine-modified silicone parting agent as a test
plate.
[0011] As a result, it has been found that, by using the latter
plate rather than the stainless steel plate as a test plate, a
difference appears between measurement values of an adhesive tape
having an excellent adhesive strength and that having an inferior
adhesive strength against the spectacle lens on which the
antifouling layer has been provided.
[0012] Further, when the adhesive tape has an adhesive strength of
4 gf or more in the adhesive strength test using this test plate,
it has been found that the adhesive tape is favorably attached to
the spectacle lens on which the antifouling layer is formed by
using the fluorine-containing silane compound. Still further, when
the adhesive tape having an adhesive strength of 4 gf or more is
interposed between the chuck of the edge-machining apparatus and
the lens, it has been found that edging can be performed without
generating an axial misalignment.
[0013] At the time of edging, a method of holding the lens by
applying pressure by the chuck of the edge-machining apparatus from
both sides of the lens is adopted. In such case, in a progressive
multifocal lens, by attaching the adhesive tape to the concave face
of the lens, it is not necessary to attach the adhesive tape on the
convex face of the lens on which various types of layout marks have
been applied. Accordingly, the edging can be performed without the
need of removing the layout marks.
[0014] Further, when the adhesive tape is attached to the convex
face of a progressing multifocal spectacle lens, in order to avoid
a mark of a fitting point which has been applied, it is preferable
to provide a bored-through hole in a center portion of the adhesive
tape.
[0015] The adhesive tape according to the present invention is an
adhesive tape which is provided between a lens and at least one of
a plurality of chucks in an edge-machining apparatus and comprises
an adhesive face for being in contact with the lens. Generally, the
plurality of chucks represents a pair. Further, a measurement value
of the adhesive strength of the adhesive face is 4 gf (0.0392 N) or
more when a polyethylene terephthalate plate which has been
subjected to a surface treatment with a fluorine-modified silicone
parting agent is used as a test plate in an adhesive strength test
method based on a 180.degree.-peeling method as defined in JIS Z
0237 "adhesive tape/adhesive sheet test method".
[0016] In one embodiment, a bored-through hole is provided in the
central portion of the adhesive tape according to the present
invention. An edging method according to the present invention
attaches an adhesive tape on an antifouling layer of a lens in
which the antifouling layer is provided. Then, the lens is held by
a plurality of chucks such that the adhesive tape is interposed
between the lens and at least one of the plurality of chucks in an
edge-machining apparatus. Thereafter, edging of the lens is
performed by the edge-machining apparatus.
[0017] Preferably, the adhesive tape comprises an adhesive face for
being contact with the lens. And, a measurement value of an
adhesive strength of the adhesive face is 4 gf (0.0392 N) or more
when a polyethylene terephthalate plate which has been subjected to
a surface treatment with a fluorine-modified silicone parting agent
is used as a test plate in an adhesive strength test method based
on a 180.degree.-peeling method as defined in JIS Z 0237 "adhesive
tape/adhesive sheet test method".
[0018] More preferably, the antifouling layer is formed by using as
a main component a fluorine-containing silane compound as
represented by the following general formula (1): 1
[0019] wherein R.sub.f represents a straight or branched
perfluoroalkyl group having from 1 to 16 carbon atoms;
[0020] X represents iodine or hydrogen;
[0021] Y represents hydrogen or a lower alkyl group;
[0022] Z represents fluorine or a trifluoromethyl group;
[0023] R.sup.1 represents a hydrolysable group;
[0024] R.sup.2 represents hydrogen or an inactive monovalent
organic group;
[0025] a, b, c, and d each individually represent an integer of
from 0 to 200;
[0026] e represents 0 or 1;
[0027] m and n each individually represent an integer of from 0 to
2; and
[0028] p represents an integer of from 1 to 10.
[0029] In another embodiment, the edging method comprises a step of
attaching the adhesive tape to the concave face of a lens.
[0030] The adhesive tape according to the present invention is an
adhesive tape which is provided between a lens and at least one of
a plurality of chucks in an edge-machining apparatus and comprises
an adhesive face for being in contact with the lens. When an
adhesive strength of the adhesive face is measured based on a
predetermined test method, a measurement value of an adhesive
strength is 4 gf (0.0392 N) or more. The predetermined test method
is basically same as an adhesive strength test method based on a
180.degree.-peeling method as defined in JIS Z 0237 "adhesive
tape/adhesive sheet test method", except for replacing a test plate
used in the adhesive strength test method based on a
180.degree.-peeling method as defined in JIS Z 0237 "adhesive
tape/adhesive sheet test method" by a polyethylene terephthalate
plate which has been subjected to a surface treatment with a
fluorine-modified silicone parting agent.
BRIEF DESCRIPTION OF THE DRAWINGS
[0031] FIG. 1(A) is a cross-sectional diagram showing an edging
method using an adhesive tape for edging according to the present
invention in a case in which the adhesive tape for edging is
attached to a convex face of a lens;
[0032] FIG. 1(B) is a cross-sectional diagram showing an edging
method using an adhesive tape for edging according to the present
invention in a case in which the adhesive tape for edging is
attached to the concave face of the lens;
[0033] FIG. 1(C) is a cross-sectional diagram showing an edging
method using an adhesive tape for edging according to the present
invention in a case in which the adhesive tape for edging is
attached to both faces of the lens;
[0034] FIG. 2 is a plan view of an embodiment of a form of an
adhesive tape for edging;
[0035] FIGS. 3(A) to 3(C) are schematic diagrams showing
cross-sectional configurations of adhesive tapes for edging;
[0036] FIG. 4 is a schematic diagram showing an edging method;
and
[0037] FIG. 5 is a schematic diagram showing an edging method.
DETAILED DESCRIPTION OF THE INVENTION
[0038] "JIS Handbook 29 Adhesion"; Japanese Standards Association,
Jan. 31, 2002, and "JIS Handbook on Steel"; Japanese Standards
Association, Apr. 12, 1989 are incorporated herein by reference in
their entirety.
[0039] Embodiments of an adhesive tape for edging and an edging
method according to the present invention are described below, but
the present invention is by no means limited thereto.
[0040] Edging of a spectacle lens, also known as edge machining,
includes grinding an edge of a round spectacle lens by a grinding
stone such that the spectacle lens can be inserted in a spectacle
frame. The spectacle lens is a meniscus lens which has a convex
face on the side of an object and the concave face on the side of
an eye ball.
[0041] FIG. 5 shows an edging method of a lens to be performed by
using an edge-machining apparatus. In the edging method, first, the
lens L is applied with pressure such that the lens L is sandwiched
from both sides of an optical axis of the lens by chucks 2, 3 of an
edge-machining apparatus. On this occasion, a lens lock tape 4 is
ordinarily attached to the convex face side of the lens L for the
purpose of scar prevention and machining positioning and a chuck 2
on the convex face side of the lens L presses against a surface of
the lens L via the lens lock tape 4. After the lens is fixed to the
chucks 2 and 3, the edge machining is performed by using the
grinding stone 5 based on frame data.
[0042] On the other hand, the spectacle the lens which has been
subjected to a surface treatment with a fluorine-containing silane
compound as described in the aforementioned publication has a small
friction coefficient compared with that treated with a conventional
surface treating agent and, accordingly, has a characteristic of
being too slippery. At the time of edging, due to the
characteristic of the surface of the lens L held by the chucks 2
and 3 being too slippery, there is a problem in that, when the lens
L is ground by a grinding stone 5, the lens L slips out of position
with respect to the chucks 2 and 3 by a grinding pressure, namely,
an axial misalignment occurs and, accordingly, a precise edging can
not be performed.
[0043] In order to solve the problem, the adhesive tape according
to the present invention is attached to the spectacle lens at the
time of edging. Specifically, the adhesive tape according to the
present invention is used such that it is interposed between the
chucks, which hold the spectacle lens, of the edge-machining
apparatus and the spectacle lens.
[0044] FIGS. 1 show three embodiments of an edging method which
uses an adhesive tape 1 for edging. Further, the adhesive tape 1
for edging of the present embodiment corresponds to the adhesive
tape according to the present invention.
[0045] In a configuration as shown in FIG. 1(A), the adhesive tape
1 for edging is positioned on a convex face of the spectacle lens
L. And, a lens lock tape 4 is positioned on the adhesive tape 1 for
edging. Further, a lens holding member (not shown) is positioned on
the lens lock tape 4. In this configuration, the adhesive tape 1
for edging, the lens lock tape 4, and the lens holding member cover
the machining center of the spectacle lens L. And, a chuck 2
presses against the lens lock tape 4 to the side of a chuck 3 via
the lens holding member while a chuck 3 presses against the
spectacle lens L to the side of the chuck 2. In such a manner as
described above, a position of the spectacle lens L is fixed
against the chucks 2, and 3. Further, respective central positions
of chucks 2 and 3 of the edge-machining apparatus correspond to the
machining central portion of the spectacle lens L.
[0046] Still further, in the present embodiment, the chucks 2 and 3
are also expressed as "lens fixing device".
[0047] A method of edging the spectacle lens L by using the
configuration as shown in FIG. 1(A) is described below. First, the
adhesive tape 1 for edging is attached onto the convex face of the
spectacle lens L such that it covers the machining central portion.
Then, the lens lock tape 4 is attached onto the adhesive tape 1 for
edging. Thereafter, the lens holding member is attached onto the
lens lock tape 4. Subsequently, the lens L which is provided with
the adhesive tape 1 for edging, the lens lock tape 4 and the lens
holding member are inserted between the chucks 2 and 3 of the
edge-machining apparatus. Then, by clamping the lens holding
member, the lens lock tape 4, the adhesive tape 1 for edging, and
the lens L with the chucks 2 and 3, a position of the lens L is
fixed. On this occasion, the chucks 2 and 3 and the spectacle lens
L are allowed to be positioned with one another such that the
respective central positions of the chucks 2 and 3 correspond to
the machining central portion of the spectacle lens L. Thereafter,
a rotating grinding stone 5 is allowed to be in contact with the
spectacle lens L to perform the edging of the spectacle lens L as
shown in FIG. 4.
[0048] In the configuration as shown in FIG. 1(B), the adhesive
tape 1 for edging is positioned on the concave face of the
spectacle lens L, whereas the lens lock tape 4 is positioned on the
convex face of the spectacle lens L. Then, the chuck 2 presses
against the lens lock tape 4 to the side of the chuck 3 via the
lens holding member (not shown) and, also, the chuck 3 presses
against the adhesive tape 1 for edging to the side of the chuck 2
to thereby fix the position of the spectacle lens L.
[0049] Further, the adhesive tape 1 for edging, the lens lock tape
4 and the lens holding member cover the machining central portion
of the spectacle lens L. The rotating grinding stone 5 is allowed
to be in contact with the spectacle lens L thus held to perform
edging of the spectacle lens L.
[0050] In the configuration as shown in FIG. 1(C), the adhesive
tape 1 for edging is positioned on each of the convex and concave
faces of the spectacle lens L. Then, the lens lock tape 4 is
positioned on the adhesive tape 1 for edging on the convex face,
and the lens holding member (not shown) is provided on the lens
lock tape 4. And, the chuck 2 presses against the lens lock tape 4
to the side of the chuck 3 via the lens holding member and, at the
same time, the chuck 3 presses against the adhesive tape 1 for
edging of the concave side to the side of the chuck 2 to thereby
fix the position of the spectacle lens L. Further, two adhesive
tapes 1 for edging cover the machining central portion of the
spectacle lens L. And, then, a rotating grinding stone 5 is allowed
to be in contact with the spectacle lens 1 which is held in the
manner as described above to perform edging of the spectacle lens
L.
[0051] In FIGS. 1(A) and 1(C), the adhesive tape 1 for edging is
attached onto the convex face of the spectacle lens L. Further, the
lens lock tape 4 is attached onto the adhesive tape 1 for edging to
perform the edging. Still further, when the lens lock tape 4 is not
used for the purpose of positioning, it is possible to omit the
lens lock tape 4. Still further, when the adhesive layer is formed
on the face of a lens opposite to the face of the adhesive tape 1
for edging, it can concurrently be used for the purpose of
positioning. Therefore, it is possible to omit the lens lock tape
4.
[0052] Further, the lens holding member of the present embodiment
has a biting tooth on the side which is in contact with the lens
lock tape 4. Since this biting tooth bites into the lens lock tape
4, the lens L can be assuredly held at the time of the lens
machining. However, the biting tooth of the lens holding member may
be omitted or the lens holding member itself may be omitted,
depending on a rotation speed of the lens L or strength of torque
to be generated by a friction between the grinding stone 5 (see
FIG. 4) and the lens L at the time of the lens machining. The
structure of the lens holding member is described in detail in JP-U
No. 6-24852, the disclosure of which is incorporated herein by
reference.
[0053] The adhesive tape 1 for edging according to the present
embodiment is used, as described above, such that it is attached to
only the concave face, only the convex face, or both of the concave
and convex faces of the spectacle lens which is subjected to an
antifouling treatment at the time of edging. Specifically, the
adhesive tape 1 is used such that it is interposed between the
chuck of the edge-machining apparatus, which holds the spectacle
lens, and the spectacle lens. As a result, a problem that the lens
is out of position against the chuck, namely, an axial
misalignment, can be prevented.
[0054] The adhesive tape 1 for edging is tested by using a
polyethylene terephthalate plate which has been subjected to a
surface treatment with a fluorine-modified silicone parting agent
as a test plate in an adhesive test method based on
180.degree.-peeling method as defined in JIS Z 0237 "adhesive
tape/adhesive sheet test method" ("JIS Handbook 29 Adhesion";
Japanese Standards Association, Jan. 31, 2002). The adhesive
strength of the adhesive tape 1 for edging measured at that time is
4 gf (0.0392 N) or more.
[0055] An outline of the adhesive strength test method based on the
180.degree.-peeling method as defined in JIS Z 0237 "adhesive
tape/adhesive sheet test method" is described below. A test is
performed under the following standard condition: a temperature in
a test place of 23.+-.2.degree. C.; and a relative humidity of
65.+-.5%. A sample must be left for 2 hours or more in an
atmosphere of the standard conditions.
[0056] The test piece is cut into a tape having a width of 25 mm or
more or a sheet having a width of 25 mm. When the tape is less than
25 mm wide, the tape is used in its original width. Three test
pieces each having such width as described above and a length of
about 250 mm are selected.
[0057] A tensile testing machine as defined in JIS B 7721 is used.
As for a test plate, an SUS 304 or SUS 302 steel plate having a
thickness of from 1.5 to 2.0 mm as defined in JIS G 4305, a width
of 50 mm and a length of 125 mm is used. A hand-operated roller is
used as a pressing apparatus. The surface of the hand-operated
roller is covered with a rubber layer having a spring hardness of
80.+-.5 Hs and a thickness of about 6 mm as defined in JIS K 6301.
The hand-operated roller has a width of about 45 mm, a diameter of
about 83 mm, and a mass of 2000.+-.50 g.
[0058] The test pieces are placed on a previously cleaned test
plate such that adhesive faces thereof face downward, and are
aligned with one another at one end thereof with a remaining
portion of 125 mm in length being set free. The adhesive face of
the remaining portion is applied with talc in powder form or
attached to paper.
[0059] A roller is reciprocated one time thereon at a speed of
about 300 mm/min. to press the test pieces. After such pressing,
the remaining portion of each of the test pieces is folded at an
angle of 180 degrees for 20 to 40 minutes. About 25 mm of the test
piece is peeled off. Thereafter, the test piece is clamped by an
upper chuck while the test plate is clamped by a lower chuck. The
test piece is peeled off at a speed of 300.+-.30 mm/min.
[0060] Every time about 20 mm of the test piece is peeled off,
strength thereof is read. Such reading is conducted four times. The
test is conducted on 3 test pieces. An average value of the
resultant 12 measurements on the 3 test pieces is determined and,
then, the average value is converted to a value per 10 mm in width
based on a proportional calculation.
[0061] A test method for determining the adhesive strength of the
adhesive tape for edging of the present embodiment is in accordance
with the aforementioned adhesive strength test method based on a
180.degree.-peeling method as defined in JIS Z 0237 "adhesive
tape/adhesive sheet test method". However, a polyethylene
terephthalate plate having a thickness of 3 mm which has been
subjected to a surface treatment with a fluorine-modified silicone
parting agent is used as a test plate. A specific production method
of the test plate in the test method of the present embodiment is
described below.
[0062] First, a fluorine-modified silicone parting agent is
uniformly applied onto a surface of a polyethylene terephthalate
plate having dimensions of 3 mm thick, 50 mm wide and 125 mm long
by, for example, a bar coat method, in an amount in the range of
from 0.3 g/m.sup.2 to 0.6 g/m.sup.2. Then, the polyethylene
terephthalate plate coated with the fluorine-modified silicone
parting agent is heated at about 150.degree. C. for about 60
seconds.
[0063] After such heating is terminated, the side of the
polyethylene terephthalate plate covered with the fluorine-modified
silicone parting agent is coated with any one of ethanol, isopropyl
alcohol and acetone as a cleaning liquid. Then, the cleaning liquid
is wiped off by, for example, gauze. Such coating of the cleaning
liquid and wiping off are repeated at least three times until the
surface of the test plate is confirmed to be clean by a visual
inspection. Further, as the fluorine-modified silicone parting
agent, X-70-20 manufactured by Shin-Etsu Chemical Co. Ltd. is
utilized in the present embodiment.
[0064] In the present embodiment, the polyethylene terephthalate
plate which has been coated with the fluorine-modified silicone
parting agent and then heated is also referred to as "polyethylene
terephthalate test plate" for convenience.
[0065] An adhesive tape in which the adhesive strength measured by
such adhesive strength test method as described above is 4 gf
(0.0392 N) or more and, preferably, 6 gf (0.0588 N) or more, is
strongly attached to a spectacle lens on which an antifouling layer
is formed by using the fluorine-containing silane compound as
described in the aforementioned publication. Thus, by interposing
the adhesive tape between the chuck of the edge-machining apparatus
and the lens, the axial misalignment at the time of edging can be
prevented. It is preferable that the adhesive strength is 400 gf or
less, but it is not limited thereto. However, when the adhesive
strength of the adhesive tape is unduly large, there is a risk in
that a reflection reducing coating or the like which is formed on
the surface of the lens may be peeled off.
[0066] The adhesive tape 1 for edging of the present invention has
a structure in which, an adhesive layer is provided on a substrate
tape. As for materials for the substrate tape, illustrated but not
limited thereto, are polyolefin-type resins such as polyethylene,
and polypropylene; polyesters such as polystyrene, and polyethylene
terephthalate; thermoplastic resins such as polyvinyl acetate,
acrylonitrile butadiene styrene (ABS), a polycarbonate, a polyvinyl
chloride resin, a polyamide, a polyimide, a cellulose acetate, and
poly(tetrafluoroethylene); thermosetting resins such as an epoxy
resin; rubber-type resins such as soft rubber, and hard rubber; and
materials for reinforcing these materials, for example, a resin
comprising fibrous material. Further, as for adhesives, illustrated
but not limited thereto are rubber-type adhesives such as natural
rubber (polyisoprene), styrene-butadiene rubber, butyl rubber, and
polyisobutylene; acrylic adhesives; silicone-type adhesives; and
vinyl acetate-type adhesives.
[0067] In order to prevent the axial misalignment at the time of
edging, it is necessary that the adhesive tape is strongly attached
to a curvature of the spectacle lens and, also, sustains a pressing
force from the chuck. In order to satisfy such requirements, it is
preferable that the substrate tape is selected based on its kinetic
properties such as tensile strength, and elastic modulus of
traction.
[0068] As for the tensile strength of the substrate tape, it is
preferable that the tensile strength as defined in JIS K 7127
"plastic film/sheet tensile test method" ("JIS Handbook on Steel";
Japanese Standards Association, Apr. 12, 1989) is 1 kgf/mm.sup.2
(9.8 N/mm.sup.2) or more. Further, as for the elastic modulus of
traction of the substrate tape, it is preferable that a value of
the elastic modulus of traction Em as defined in the aforementioned
JIS K 7127 "plastic film/sheet tensile test method" is in the range
of from 1 kgf/mm.sup.2 to 450 kgf/mm.sup.2 (from 9.8 N/mm.sup.2 to
4410 N/mm.sup.2). The elastic modulus of traction refers to a
region in which stress and strain are in proportion conforms to the
Hooke's law. When the value of the elastic modulus of traction of
the substrate tape is unduly small, a large elongation is generated
by a small load. As a result, there is a possibility that an axial
misalignment may occur. On the other hand, when the value of the
elastic modulus of traction of the substrate tape is unduly large,
there is a possibility that it may be difficult to trace along a
lens shape.
[0069] The thickness of the substrate tape is 10 .mu.m or more,
preferably 20 .mu.m or more, and most preferably 30 .mu.m or more.
Further, the maximum thereof is approximately 1 mm. The thickness
of the adhesive layer is preferably in the range of from 1 .mu.m to
100 .mu.m. Still further, as for an area of the adhesive surface of
the adhesive tape for edging, in order to secure the necessary
adhesive strength against the spectacle lens, it is preferable to
secure 700 mm.sup.2 or more when the aforementioned adhesive
strength is from 4 gf (0.0392 N) to 8 gf (0.0784 N) and 400
mm.sup.2 or more when it is 8 gf (0.0784 N) or more.
[0070] A form of the substrate tape is not particularly limited so
long as it has the aforementioned area. For example, a round,
elliptical, or oblong shape may be used. However, as shown in FIGS.
1(A) and 1(C), when the spectacle lens is a progressive multifocal
lens and the adhesive tape is attached to the convex face thereof,
it is preferable that it is shaped such that it does not overlap a
layout pattern which has been printed on the convex face of the
progressive multifocal lens.
[0071] As shown in FIG. 2, in the convex face of the progressive
multifocal lens, various types of layout patterns are marked with
solvent-removable ink. These layout patterns are layout markings
of, for example, a horizontal reference line 101 showing a
horizontal direction of the spectacle lens, a distance power
measuring position 102 showing a position at which a power of a
distance portion is measured, a near power measuring position 103
showing a position at which a power of a near portion is measured,
a fitting point 104, and a right-or-left recognition mark 105.
[0072] The adhesive tape 1 for edging according to the present
invention is attached onto the fitting point 104 which shows an
optical center. The marking of the layout pattern printed on the
spectacle lens in which an antifouling layer is formed is easily
removable. For this reason, when the adhesive tape 1 for edging is
attached onto the layout pattern, ink of the layout pattern is
attached to the adhesive tape 1 for edging. As a result, there is a
risk that the layout pattern is eliminated from the surface of the
spectacle lens L. It is necessary to keep the layout pattern as it
is even after the edging is performed. For this account, in the
adhesive tape 1 for edging, as shown in FIG. 2, a bored-through
hole 11 is provided in the central portion thereof such that it
does not overlap the fitting point 104 and the outer configuration
is formed to be round, elliptical or oblong such that the adhesive
tape does not overlap the distance power measuring position 102
provided on the fitting point 104.
[0073] As shown in FIG. 1(B), when the adhesive tape 1 for edging
is attached onto the concave side of the spectacle lens L, since
nothing is printed on the concave side of the spectacle lens L, the
form thereof is not limited. In order to enhance the adhesive
strength, the area of the adhesive lens 1 can be enlarged. For
example, the adhesive tape 1 can be attached onto an entire concave
face of the spectacle lens.
[0074] Structures of the adhesive tape 1 for edging and a lens lock
tape 4 are described in detail below.
[0075] The adhesive tape 1 for edging as shown in FIG. 3(A)
comprises an adhesive layer 1a and a substrate tape 1b. The
substrate tape 1b has a first face and a second face which face
different directions from each other. The adhesive layer 1a is
positioned on the first face of the substrate tape 1b. According to
the present embodiment, a measurement value of the adhesive layer
1a in the adhesive tape 1 for edging is 4 gf (0.0392 N) or more in
the test method of the present embodiment. Further, the adhesive
layer 1a provides an adhesive face for allowing the adhesive layer
1a to be in contact with the lens L in the adhesive tape 1 for
edging.
[0076] On the other hand, the lens lock tape 4 as shown in FIG.
3(A) comprises an adhesive layer 4a, a substrate tape 4b and an
adhesive layer 4c. The substrate tape 4b has a first face and a
second face which face different directions from each other. And,
the adhesive layer 4a is positioned on the first face of the
substrate tape 4b. Further, the adhesive layer 4c is positioned on
the second face of the substrate tape 4b. Since the adhesive
portions (adhesive layers 4a and 4c) are provided on both faces
(that is, the first and second faces) of the substrate tape 4b, the
lens lock tape 4 has a function of a so-called double-faced
adhesive tape.
[0077] When a lens machining work such as the edging is performed,
a lens holding member (not shown) is attached onto the adhesive
layer 4c. The adhesive tape 1 for edging is provided such that the
adhesive layer 1a and the lens L are in contact with each other.
Further, the lens lock tape 4 is provided such that the adhesive
layer 4a and the second face of the substrate tape 1b are in
contact with each other. In addition, the lens holding member on
the adhesive layer 4c and the chuck 2 are in contact with each
other. By applying pressure to a place between the chuck 2 and the
chuck 3 (see FIG. 1), the lens L can be held between the chuck 2
and the chuck 3.
[0078] The aforementioned lens holding member of the present
embodiment has a biting tooth on the side which contacts the
adhesive layer 4c. Since the biting tooth bites into the adhesive
layer 4c, the lens L is more securely held at the time of lens
machining. However, the biting tooth of the lens holding member or
the lens holding member itself may be omitted, depending on a
rotation speed of the lens L or strength of torque to be generated
by a friction between the grinding stone 5 (see FIG. 4) and the
lens L at the time of machining.
[0079] The configurations in which the biting tooth of the lens
holding member and the lens holding member itself are omitted are
shown in FIGS. 3(B) and 3(C), respectively. As mentioned above, the
structure of the lens holding member is described in detail in JP-U
No. 6-24852, an explanation thereon is omitted herein.
[0080] The adhesive tape 1 for edging as shown in FIG. 3(B)
comprises an adhesive layer 1a, a substrate tape 1b and an adhesive
layer 1c. The substrate tape 1b has a first face and a second face
which face different directions from each other. And, the adhesive
layer 1a is positioned on the first face of the substrate tape 1b
and, at the same time, the adhesive layer 1c is positioned on the
second face of the substrate tape 1b. According to the present
embodiment, a measurement value of the adhesive strength of the
adhesive layer 1a in the adhesive tape 1 for edging is 4 gf (0.0392
N) or more in the test method of the present embodiment. However,
the measurement value of the adhesive strength of the adhesive
layer 1c in the adhesive tape 1 for edging is not necessarily 4 gf
or more in the test method according to the present embodiment.
Further, since the adhesive portions (that is, adhesive layers 1a
and 1c) are provided on both faces (that is, first and second
faces) of the substrate tape 1b, the adhesive tape 1 for edging has
a function of a double-faced tape. Further, the adhesive layer 1a
provides an adhesive face for being in contact with the lens L in
the adhesive tape 1 for edging.
[0081] When a lens machining work such as edging is performed, the
lens holding member (not shown) is adhered onto the adhesive layer
1c. And, the adhesive layer 1a and the lens L are in contact with
each other and, at the same time, the adhesive tape 1 for edging is
arranged such that the lens holding member provided on the adhesive
layer 1c and the surface of the chuck 2 are in contact with each
other. Then, by applying pressure to a place between the chuck 2
and chuck 3 (see FIG. 1), the lens L is held between the chuck 2
and the chuck 3.
[0082] Since the adhesive layer is provided not only on the first
face of the substrate tape 1b but also on the second face thereof,
it is not necessary to provide the lens lock tape 4 between the
chuck 2 and the lens L. Namely, the tape 1 for edging
simultaneously has a function of the lens lock tape 4.
[0083] The adhesive tape 1 for edging as shown in FIG. 3(C)
comprises an adhesive layer 1a, a first substrate tape 1b, an
adhesive layer 1c, a second substrate tape 1b', and an adhesive
layer 1d. The first substrate tape 1b has a first face and a second
face which face different directions from each other. And, the
adhesive layer 1a is positioned on the first face of the first
substrate tape 1b and, at the same time, the adhesive layer 1c is
positioned on the second face of the first substrate tape 1b.
[0084] The second substrate tape 1b' has a first face and a second
face which face different directions from each other. The first
face of the second substrate tape 1b' is in contact with the
adhesive layer 1c. Namely, the first substrate tape 1b and the
second substrate tape 1b' are in contact with each other indirectly
through the adhesive layer 1c. On the other hand, the adhesive
layer 1d is positioned on the second face of the second substrate
tape 1b'.
[0085] According to the present embodiment, a measurement value of
the adhesive layer 1a in the adhesive tape 1 for edging is 4 gf
(0.0392 N) or more in the test method of the present embodiment.
However, measurement value of the adhesive strength of the adhesive
layers 1c and 1d in the adhesive tape 1 for edging are not
necessarily 4 gf or more in the test method of the present
embodiment. The adhesive layer 1a provides an adhesive face for
being in contact with the lens L in the adhesive tape 1 for
edging.
[0086] When a lens processing work such as edging is performed, the
lens holding member (not shown) is adhered on the adhesive layer
1d. The adhesive layer 1a and the lens L are in contact with each
other. The adhesive tape 1 for edging is arranged such that the
lens holding member provided on the adhesive layer 1d and the
surface of the chuck 2 are in contact with each other. Then, by
applying pressure between the chuck 2 and chuck 3 (see FIG. 1), the
lens L is fixed between the chuck 2 and the chuck 3.
[0087] The edging method using the adhesive tape for edging
according to the present invention does not generate the axial
misalignment when the spectacle lens in which the antifouling layer
is provided on a surface of the spectacle lens (namely, a slippery
spectacle lens) is machined. It goes without saying that an edging
method using the adhesive tape for edging according to the present
embodiment does not generate the axial misalignment when the lens
which does not have an antifouling layer is machined.
[0088] A material for the spectacle lens may be either inorganic
glass or plastic. As for such plastics, mentioned are a diethylene
glycol bisallylcarbonate (CR-39) resin, a polyurethane resin, a
thiourethane resin, a polycarbonate resin, an acrylic resin and the
like.
[0089] As for the antifouling layer, for example, a
fluorine-containing silane compound which has been difficult to be
subjected to edging as represented by the following general formula
(1) is preferably used as a main component: 2
[0090] wherein R.sub.f represents a straight or branched
perfluoroalkyl group having from 1 to 16 carbon atoms and
preferably CF.sub.3--, C.sub.2F.sub.5--, or C.sub.3F.sub.7--;
[0091] R.sup.1 represents a hydrolysable group and preferably, for
example, a halogen, --OR.sup.3, --OCOR.sup.3,
--OC(R.sup.3).dbd.C(R.sup.4- ).sub.2, --ON.dbd.C(R.sup.3).sub.2, or
--ON.dbd.CR.sup.5 and more preferably chlorine, --OCH.sub.3,
--OC.sub.2H.sub.5;
[0092] R.sup.3 represents an aliphatic hydrocarbon group or an
aromatic hydrocarbon group;
[0093] R.sup.4 represents hydrogen or a lower aliphatic hydrocarbon
group;
[0094] R.sup.5 represents a divalent aliphatic hydrocarbon group
having from 3 to 6 carbon atoms;
[0095] R.sup.2 represents hydrogen or an inactive monovalent
organic group and preferably a monovalent hydrocarbon group having
from 1 to 4 carbon atoms;
[0096] a, b, c, and d each individually represents an integer of
from 0 to 200, and preferably from 1 to 50;
[0097] e represents 0 or 1;
[0098] m and n each individually represents an integer of from 0 to
2, and preferably 0;
[0099] P represents an integer of 1 or more, and preferably an
integer of from 1 to 10. Further, a molecular weight is from
5.times.10.sup.2 to 1.times.10.sup.5, and preferably from
5.times.10.sup.2 to 1.times.10.sup.4.
[0100] Further, as one of preferable structures of the
fluorine-containing silane compound represented by the
aforementioned general formula (1), mentioned is a compound
represented by the following general formula 3
[0101] wherein Y represents hydrogen or a lower alkyl group;
[0102] R.sup.1 represents a hydrolysable group;
[0103] q represents an integer of from 1 to 50;
[0104] m represents an integer of from 0 to 2; and
[0105] r represents an integer of from 1 or less to 10 or more.
[0106] In order to form the antifouling layer in the spectacle lens
by using the aforementioned fluorine-containing silane compound, a
method in which the compound is dissolved in an organic solvent
and, then, applied on a surface of the spectacle lens can be
adopted. As for application methods, mentioned are a dipping
method, a spin coat method, a spray method, a flow method, a doctor
blade method, a roll coat coating, a gravure coat coating, a
curtain flow coating and the like. As for such organic solvents,
mentioned are perfluorohexane, perfluoromethylcyclohexa- ne,
perfluoro-1,3-dimethylcyclohexane and the like.
[0107] When diluted with the organic solvent, a concentration of
the fluorine-containing silane compound is preferably in the range
of from 0.03 wt % to 1 wt %. When the concentration of the compound
is unduly low, since it is difficult to form the antifouling layer
having a sufficient thickness, a satisfactory antifouling effect
can not be obtained. On the other hand, when the concentration of
the compound is unduly high, there is a risk that a film thickness
of the antifouling layer becomes too thick. For this reason, after
the compound is applied, there is a risk of increasing a work load
such that a rinse operation may be required to eliminate coating
unevenness.
[0108] Further, as for application methods of the
fluorine-containing silane compound, a vacuum evaporation method in
which the fluorine-containing silane compound is allowed to be
evaporated in a vacuum tank and, then, deposited on a surface of
the spectacle lens can also be adopted. In the vacuum evaporation
method, a material compound can be used in a high concentration or
without using a diluent solvent.
[0109] The thickness of the antifouling layer is not particularly
limited, but generally is from 0.001 .mu.m to 0.5 .mu.m and,
preferably, from 0.001 .mu.m to 0.03 .mu.m. When the film thickness
of the antifouling layer is unduly small, the antifouling effect
becomes scarce. Whereas when the thickness thereof is unduly large,
the surface becomes sticky, which is not favorable. Further, when
the antifouling layer is provided on a surface of a reflection
reducing coating, the thickness of the antifouling layer of 0.03
.mu.m or more deteriorates a reflection reducing effect, which also
not favorable.
[0110] The edging method according to the present embodiment is
applied to the spectacle lens having an antifouling layer
comprising the fluorine-containing silane compound represented by
the aforementioned general formula (1) as a main component. Namely,
the adhesive tape for edging according to the present invention is
attached to only the convex face, only the concave face, or both of
these faces at the time of edging. Then, the adhesive tape is used
in a state of being interposed between the chuckof the
edge-machining apparatus, which holds the spectacle lens, and the
spectacle lens. As a result, the axial misalignment in which the
lens comes out of position against the chuck can be prevented.
EXAMPLE
[0111] An embodiment according to the present invention will be
described below. Four types of adhesive tapes for edging were used
as follows:
[0112] Adhesive tape A for edging:
[0113] Adhesive tape EXP 403-10 manufactured by Sun A Kaken Co.,
Ltd. (substrate sheet: polyethylene having a thickness of 60 .mu.m;
and adhesive layer: acrylic type having a thickness of 20 .mu.m)
was prepared as an adhesive tape A for edging. When the adhesive
strength of the adhesive tape A for edging against a PET
(polyethylene terephthalate) plate having a thickness of 3 mm which
has been treated with X-70-201 (manufactured by Shin-Etsu Chemical
Co., Ltd.) was measured in accordance with an adhesive test method
based on a 180.degree.-peeling method as defined in JIS Z 0237
"adhesive tape/adhesive sheet test method", the result was 4 gf
(0.0392 N). This adhesive tape A for edging was cut in elliptical
form having a vertical width of 25 mm and a horizontal width of 40
mm, provided with a bored-through hole having a diameter of about 6
mm in the center (adhesive area: 757.12 mm.sup.2) and, then, put in
use.
[0114] Adhesive Tape B for Edging:
[0115] Adhesive tape 731A manufactured by Sun A Kaken Co., Ltd. (PE
sheet substrate having a thickness of 60 .mu.m; and acrylic
adhesive having a thickness of 10 .mu.m) was prepared as an
adhesive tape B for edging. When adhesive strength of the adhesive
tape B for edging against a PET plate having a thickness of 3 mm
which has been treated with X-70-201 (manufactured by Shin-Etsu
Chemical Co., Ltd.) was measured in accordance with an adhesive
test method based on a 180.degree.-peeling method as defined in JIS
Z 0237 "adhesive tape/adhesive sheet test method", the result was 8
gf (0.0784 N). This adhesive tape B for edging was cut in round
form having a diameter of 25 mm, provided with a bored-through hole
having a diameter of 6 mm in the center (adhesive area: 462.60
mm.sup.2 ) and, then, put in use.
[0116] Adhesive Tape C for Edging:
[0117] A both-faced adhesive seal comprising a substrate sheet
containing neoprene foam having a thickness of 1 mm and an acrylic
adhesive layer of 20 .mu.m was prepared as an adhesive tape C for
edging. When the adhesive strength of the adhesive tape C for
edging against a PET (polyethylene terephthalate) plate having a
thickness of 3 mm which has been treated with X-70-201
(manufactured by Shin-Etsu Chemical Co., Ltd.) was measured in
accordance with an adhesive test method based on a
180.degree.-peeling method as defined in JIS Z 0237 "adhesive
tape/adhesive sheet test method", the result was 10 gf. This
adhesive tape C for edging was cut in round form having a diameter
of 25 mm, provided with a bored-through hole having a diameter of 6
mm in the center (adhesive area: 462.60 mm.sup.2) and, then, put in
use.
[0118] Adhesive Tape D for Edging (Comparison):
[0119] Adhesive tape EXP 403-30 manufactured by Sun A Kaken Co.,
Ltd. (substrate sheet: polyethylene having a thickness of 60 .mu.m;
and adhesive: acrylic type having a thickness of 10 .mu.m) was
prepared as an adhesive tape D for edging. When the adhesive
strength of the adhesive tape D for edging against a PET
(polyethylene terephthalate) plate having a thickness of 3 mm which
has been treated with X-70-201 (manufactured by Shin-Etsu Chemical
Co., Ltd.) was measured in accordance with an adhesive test method
based on a 180.degree.-peeling method as defined in JIS Z 0237
"adhesive tape/adhesive sheet test method", the result was 2 gf.
This adhesive tape D for edging was cut in elliptical form having a
vertical width of 25 mm and a horizontal width of 40 mm, provided
with a bored-through hole having a diameter of about 6 mm in the
center (adhesive area: 757.12 mm.sup.2) and, then, put in use.
[0120] By using the thus-prepared four types of adhesive tapes for
edging, edging tests were conducted in a manner as described below.
However, since the adhesive tape C for edging simultaneously has a
function of the lens lock tape 4, tests 1 and 3 were conducted
without using the lens lock tape 4.
[0121] Test 1:
[0122] As shown in FIG. 1(A), by each individually applying
adhesive tapes A, B, C, and D for edging on a convex face of the
lens L, respective axial misalignment tests were conducted.
[0123] Test 2:
[0124] As shown in FIG. 1(B), by each individually applying
adhesive tapes A, B, C, and D for edging on the concave face of the
lens L, respective axial misalignment tests were conducted.
[0125] Test 3:
[0126] As shown in FIG. 1(C), by each individually applying
adhesive tapes A, B, C, and D for edging on both faces of a convex
face and the concave face of the lens L, respective axial
misalignment tests were conducted.
[0127] Further, as for the lens, a spectacle plastic lens (Seiko
Super-Sovereign Raku Care coat, manufactured by Seiko Epson
Corporation, in which an antifouling layer has been formed by
performing a surface treatment with the fluorine-containing silane
compound as described in the aforementioned publication) having
powers of S=-7.00D and C=-3.00D was used.
[0128] Axial misalignment evaluation tests were conducted on these
adhesive tapes for edging as described below.
[0129] Test method:
[0130] The present evaluation was conducted by observing presence
or absence of axial misalignment generation derived from slipping
between a chuck portion (position in which lens is fixed to an axis
of machining apparatus) and a surface of a lens, when the lens L is
ground into a predetermined frame shape by using an edge-machining
apparatus.
[0131] First, a test lens is prepared and, then, set to a lens
fixing jig. At this time, the lens having astigmatism is fixed such
that a cylinder axis is set to be in a predetermined direction (for
example, 180.degree.). Further, the lens having no astigmatism was
ruled with a direct line which passes through an optical center of
the lens. Then, the lens is fixed such that the direct line is set
to be in a predetermined direction (for example, 180.degree.). A
half-eye type frame having a large aspect ratio is prepared to
thereby be a reference frame.
[0132] Optionally, an adhesive tape for edging is attached to the
convex or concave face of the lens. A lens lock tape is attached to
the convex face of the lens. The resultant lens is fixed to an
edge-machining apparatus ("LE-8080" manufactured by NIDEK Co.,
Ltd.) and, then, edge machining was performed based on previous
frame data. The lens subjected to the edge machining is inserted
into the reference frame and, then, is put to a measurement of
misalignment of the cylinder axis by using a lens meter. When the
direct line which passes through the optical center of the lens was
ruled, a misalignment angle between such ruled line and a
horizontal line which passes through an optical axis of the
reference frame was measured.
[0133] Ten lenses were subjected to the edge machining and a ratio
in which the axial misalignment is out of an allowable range was
calculated. The allowable range of the axial misalignment was set
to be .+-.2.degree..
[0134] The evaluation test results of the axial misalignment of the
adhesive tape for edging are shown in Table 1. Further, occurrence
of the axial misalignment was 100% when the edging was performed in
a conventional method without using the adhesive tape for
edging.
1TABLE 1 Evaluation test results of axial misalignment of tape for
edging Adhesive tape Adhesive tape Adhesive tape Adhesive tape D
for edging A for edging B for edging C for edging (Comparison)
Adhesive strength (gf) 4 8 10 2 Adhesive area (mm.sup.2) 757.12
462.60 462.60 757.12 Occurrence of Test 1 (convex 0 0 0 100 axial
face used misalignment Test 2 (concave 0 0 0 100 (%) face used Test
3 (both 0 0 0 80 faces used)
[0135] The adhesive tape 1 for edging according to the present
embodiment was attached to both of the convex and concave faces of
the spectacle lens and the resultant spectacle lens was interposed
between chucks of the edge-machining apparatus. As a result, as
seen from Table 1, it was recognized that the adhesive tape 1
allows the edge machining to be performed without generating an
axial misalignment even against an extremely slippery spectacle
lens in which an antifouling layer was formed by performing a
surface treatment by using the fluorine-containing silane
compound.
[0136] The adhesive tape 1 for edging according to the present
embodiment is attached to a spectacle lens at the time of edging
and, then, used such that it is interposed between a chuck of the
edge-machining apparatus, which holds the spectacle lens, and the
spectacle lens. By taking such configuration, even when a slippery
antifouling layer is formed on a surface of the spectacle lens, an
axial misalignment does not occur between the adhesive tape 1 and
the lens. As a result, edging can be performed.
[0137] Further, by using the edging method according to the present
embodiment, even when a slippery antifouling layer is formed on the
spectacle lens, edging can be performed without causing the axial
misalignment.
[0138] An example of applying the present invention to edging of
the spectacle lens is explained; however, the present invention is
not limited to the spectacle lens, but can be applied to edging of
an ordinary lens.
[0139] Industrial Applicability
[0140] The present invention can be applied to an antifouling-type
spectacle lens, but is by no means limited thereto.
[0141] Although the invention has been described with respect to
specific embodiments, the details are not to be construed as
limitations, for it will become apparent that various embodiments,
changes and modifications may be resorted to without departing from
the spirit and scope thereof, and it is understood that such
equivalent embodiments are intended to be included within the scope
of this invention.
* * * * *